Knowledge of corneal epithelial thickness patterns in normal and abnormal refractive surgery cases may be beneficial in close-call clinical judgements. The epithelium is not of homogeneous depth over the Bowman layer and often compensates for stromal surface irregularities, becoming thicker over valleys and thinner over hills where the stroma protrudes, as it attempts to minimise abrupt changes in stromal thickness.
As a result, the anterior cornea may appear smoother on topography compared with the underlying anterior stroma. Therefore, assessment based on topography and total corneal pachymetry with no knowledge of epithelial depth may be misleading, and result in an incorrect assessment of preoperative keratoconus and postrefractive surgery ectasia progression.
As a result, I incorporate preoperative and postoperative corneal epithelial thickness mapping into my care of refractive surgery patients.